1. Field of the Invention
The present invention relates to the fabrication of dental prostheses, and more particularly to a vertically-adjustable fixator for holding dental casts during optical scanning thereof for preparation of a dental prosthesis.
2. Description of the Related Art
Three-dimensional (3D) optical scanners are commonly used in dentistry in order to create a 3D digital image of dental cast. Such 3D digital images can then be used with a milling machine or the like for fabrication of a dental prosthesis. An example of a commonly used 3D optical scanner used in dentistry is the Ceramill® Map400 scanner, manufactured by Amann Girrbach® GmbH of Germany. In order to properly position the dental cast within the optical scanning range of the scanner, the dental cast is typically supported by a transfer kit, such as exemplary transfer kit 100 of FIG. 2. As shown in FIG. 2, such a transfer kit 100 typically includes a fixator 112, which includes an upper plate 114 and a lower plate 116, both secured to, and separated by, a vertical support 118. The dental cast C is held therebetween for scanning. The lower plate 116 is secured to a fixation plate 120, which is adapted for mounting to the particular type of base plate used in the optical scanner. As shown, since the dental cast C must be held at a certain height within the optical scanning range of the scanner, one or more distance plates 122 may be connected to the fixation plate 120 for adjustably raising the height of the dental cast C with respect to the base plate in the scanner. The distance plates 122 are also adapted for secure mounting to the particular base plate used with the particular scanner.
Although such transfer kits are commonly available for use with a variety of optical scanners, assembling the various elements together for proper positioning of the dental cast can be very time consuming and also susceptible to human error, both in the assembly itself and in misjudging proper height and alignment of the dental cast with respect to the scanning range of the scanner. Thus, an adjustable fixator for scanning dental casts solving the aforementioned problems is desired.